A Christian legal rights group has asked Scotland Yard to inform its police officers that street preachers have free speech rights.

In a letter to Sir Bernard Hogan-Howe, the Metropolitan Police commissioner, the Christian Legal Centre insists that human rights laws allow Christians to express their genuinely held views without fear of arrest, providing they do not incite a breach of the peace, according to a report in the Daily Telegraph.

The letter comes about month after American Tony Miano, 49, was held by Met Police officers for almost seven hours, had his fingerprints and a DNA sample taken, and was questioned about his faith, after delivering a sermon outside a shopping center in Wimbledon, a southwest district of London, according to the Telegraph.

The Christian Post reported that Miano, a former Los Angeles Country sheriff's deputy, said following his arrest the sermon he delivered the day of his arrest was focused on all sexual immorality, not just homosexuality.

"The CLC, which is representing Miano, added in the letter that there have reportedly been at least 16 cases of Christians being arrested for expressing their beliefs on homosexuality in the past 11 years in Britain," the Post reported. "The Christian legal group has announced that it will launch legal proceedings against Scotland Yard if it does not issue guidelines protecting the free speech rights of Christians."

News reports of the arrest in early July stated that Miano was arrested after a passerby complained. The CLC letter noted that the complainant had shouted an expletive at Miano, according to Christianity Today.

"The police officers in this case found that the complainant saying (the expletive) was non-offensive and lawful, but that the evangelist's preaching from the Bible was an arrestable offence," CT reported, quoting from the letter from CLC executive director Andres Williams.

"We would like to see clear guidance from the Metropolitan Commissioner that Christians preaching from the Bible that homosexual conduct is sinful is lawful free speech," Williams said. "Free speech is under threat and we need to protect it. We hope that the Commissioner will take a lead in this.

The Telegraph reported that the CLC is also asking the Association of Chief Police Officers to draw up guidelines for police officers in other forces across England and Wales.